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ARMRIT STUDY SHEET 2026 ACCURATE SOLUTION COLLECTION
Typology: Exams
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โ for MRI magnets, the specification for field homogeneity that is considered acceptable is: A) 5-10ppm B) 10-15ppm C) 20-30ppm D) 40-50ppm. Answer: 20-30ppm โ the primary factor of an inversion recovery pulse sequence is which of the following parameters? A) TR B) TE C) TI D) FSE E) MRA. Answer: TI โ of the different types of coils used in MRI, which type(s) are found only in the housing of the main magnet?
A) surface coils B) radio frequency coils C) Heimholtz coils D) shim/gradient coils E) all. Answer: shim/gradient coils โ which of the following causes of artifacts on MR images is most commonly mistaken for a pathological signal? A) eddy currents B) magnetic susceptibility C) chemical shift D) untuned RF coils E) ferromagnetic object. Answer: chemical shift โ of the following anatomical structures, which is considered to be normally enhancing post gadolinium injection? A) cerebellum B) choroid plexus C) intervertebral disc D) auditory nerves
โ there are ____________ of _____________ serving the purpose of providing spatial information within the MR signal A) 3 pairs/ gradient coils B) 2 pairs/ shim coils C) 2 pairs/ RF amplifiers D) 6 pairs/ solenoid coils. Answer: 3 pairs/ gradient coils โ the temperature of the liquid helium in which the electromagnetic coil is immersed is appoximately: A) 32 degree F B) 0 degree k C) - 40 degree C D) - 436 degree F E) - 4 degree C. Answer: - 436 degree F โ cooling the electromagnetic coil windings to the point of supeconductivity and then inducing an electric current from an external power supply until the magnet is a full power is called: A) ramping up B) resistance load C) quench
D) boot E) topping off. Answer: ramping up โ Following the injection of a gadolinium enhancement agent, the pulse sequence most commonly employed is a: A) T2 weighted B) gradient echo C) T1 weighted D) proton density E) inversion recovery. Answer: T1 weighted โ all FDA approved gadolinium enhancement agents for MRI are administered at the same dose, it is: A) 0.1mmols/kg B) 0.01mmols/kg C) .001mmols/kg D) 1.0mmols/kg E) 10.0mmols/kg. Answer: 0.1mmols/kg
Answer: contrast to noise ratio โ in spatial localization, an efficient digital implementation of the mathematical method for converting a time varying signal into its frequency and/or phase components that is actually performed by the MRI computer is known as: A) fourier transform B) fast fourier transform C) free induction decay D) fast spin echo. Answer: fast fourier transform โ a paramagnetic, rare earth substance, attached to a chelating ligand for MRI enhancement purposes is: A) ferric chloride B) gallium C) gadolinium D) ferric nitrate E) Mn(II)salts. Answer: gadolinium โ In 1990, Lauffer described 2 types of enhancement media, the mechanism of the T1 agent is to:
A) increase T1 relaxation time, therefore emitting low signal B) decrease T1 relaxation time, therefore emitting low signal C) increase T1 relaxation time, therefore emitting high signal D) decreasing T1 relaxation time, therefore emitting high signal. Answer: increase T1 relaxation time, therefore emitting high signal โ In 1990, Lauffer described 2 types of enhancement media, the mechanism of the T2 agent is to: A) increase T2 relaxation time, therefore emitting low signal B) decrease T2 relaxation time, therefore emitting low signal C) increase T2 relaxation time, therefore emitting high signal D) decreasing T2 relaxation time, therefore emitting high signal. Answer: increase T2 relaxation time, therefore emitting low signal โ of the following enhancement agents, which is still investigation? A) hepatobiliary B) liver/spleen C) blood pool D) tumor specific E) all. Answer: all
B) Gd-HP-DO3A C) Gd-DTPA-BMA D) all. Answer: all โ enhancement can be demonstrated on which of the following pulse sequences post gadolinium injection: A) T1 weighted B) gradient-echo C) inversion recovery D) all. Answer: all โ SAR (specific absorption rate), set by the FDA, is the rate that RF energy is introduced to body tissue, measured in watts per kilogram. true or false. Answer: true โ the maximum exposure of the head and trunk to the main magnetic field (B0) is: A) 2T B) 3T
e) 6T. Answer: 3T โ the maximum exposure of extremities to the main magnetic field (B0) is: A) 2T B) 3T C) 4T D) 5T e) 6T. Answer: 5T โ exposure to gradient magnetic fields are based on the premise that the fields should be too weak to cause neuromuscular stimulation by at least a factor of 3. true or false. Answer: true โ maximum exposure to gradient magnetic fields are set at a rate of A) 3T/ second
B) 1 degree C C) 2 degrees F D) 2 degrees C E) 3 degree K. Answer: 1 degree C โ currently, patients and personnel are excluded from exposure to MRI for the 1st trimester of pregnancy true or false. Answer: true โ guidelines excluding pregnant individuals from MRI is mainly to protect the individual from: A) main magnetic field B) Radio frequency C) gradient magnetic fields D) cryogen boil off. Answer: radio frequency โ of the following categories of patients, the one that would not present any special safety considerations is: A) patient with cardiac pacemaker
B) patient on life support systems C) patients with previous arthroscopic knee surgery D) patients with a history of employment as a metal worker. Answer: patients with previous arthroscopic knee surgery โ the _____________ is a level of dose below which no response will be elicited A) Specific absorption dose B) dose equivalent C) threshold dose D)dose response curve. Answer: threshold dose โ local exposures to the RF are: less than 38 degrees C in the head, less than 39 degrees C in the trunk, less than 40 degree C in the extremities true or false. Answer: true โ patients with cardiac pacemakers are only contraindicated for an MRI scan in main magnets of more than 0.5T. true or false. Answer: false
โ being a relatively new field in medicine, the radio-biological questions about MRI, including delayed response concerns, are still unanswered. true and false. Answer: true โ in the enviornment of an MR main magnetic field, most implants that cause a deflection are considered safe for imaging. true and false. Answer: false โ once the MRI patient is comfortable and apparently has no problem with the overall procedure, it is acceptable for the technologist to leave the scanning area while a long scan is underway. true or false. Answer: false โ to avoid any possibility for a ferromagnetic object becoming a projectile, it would be advisable and safer to have the patient remove all metal objects from their person prior to the scan true or false. Answer: true
โ given tissue sample containing 10^23 mobile hydrogen protons, it can be safety assumed that approximately __________of those protons will __________ to the static magnetic field A) 10^23/ align antiparallel B) 10^17/align parallel C) 10^6/ precess perpendicular D) 10^12/ align parallel. Answer: 10^17/ align parallel โ the larmor, precessional or resonance frequency of hydrogen proton in a static magnetic field of 1.0T is approximately: A) 42.576 MHz B) 63.864 MHz C) 25.5456 MHz D) 21.288 MHz. Answer: 42.576 MHz โ when the net magnetization in the XY plane has ceased to exist the condition of __________ has been reached. A) saturation B) equilibrium C) rephasing
D) gradient. Answer: flip angle & nutration โ following the excitation pulse, the FID decays________. A) linearly B) exponentially C) during the 180 degree RF pulse D) along the Z axis. Answer: exponentially โ the MR signal is strongest when the precessing nuclei are ____________. A) in phase coherence B) at equilibrium C) aligned with B D) out of phase. Answer: in phase coherence โ measurement of the magnetic field strength outside the bore of the MR image is most typically expressed in units of ___________. A) gauss B) tesla
C) megahertz D)magnetogyric. Answer: gauss โ Nuclei in their natural enviornment (in the absence of a significant magnetic field) are aligned __________. A) with magnetic north B) randomly C) parallel D) transverse E) anti-parallel. Answer: randomly โ _________ occurs when the frequency of the RF pulse matched the frequency of the precessing nuclei. A) dephasing B) resonance C) relaxation D) saturation. Answer: resonance โ T2 is the characteristic time constant for _________.
